【Objective】As an important connecting part of new energy vehicles, special vehicles, locomotives and other means of transportation, rubber bushing plays a crucial role in the stability of the whole vehicle handling. In order to avoid the tedious work of repeated debugging in engineering practice,【Method】an optimal design method of rubber bushing all-directional stiffness (radial, axial, yaw and torsional stiffness) taking into account the material hardness and diameter reduction is proposed. Firstly, the Ogden model is used as the constitutive model of rubber bushing. Second, by combining experimental design with finite element analysis, the isotropic stiffness of rubber bushing with different inner core outer diameter, rubber height, diameter reduction and material hardness is calculated. The second-order response surface model of isotropic stiffness is established and the accuracy of the model is verified by Latin hypercube sampling and variance analysis. Finally, a multi-objective optimization method of isotropic stiffness of rubber bushing is proposed using genetic algorithm to testify the optimization result.【Result】The result shows that the relative errors between the measured radial, axial, yaw and torsional stiffness and objective stiffness are 7.72%, 9.06%, -6.33% and 9.16% respectively, which are all within ±10% and meet the requirements of engineering application.【Conclusion】The validity of the established second-order response surface model of isotropic stiffness and the feasibility of the proposed optimization design method are verified to provide guidance for the product design of rubber bushing, which can greatly shorten the research and development cycle of rubber bushing.